# Manuel Bouyer 2007-01-12:
> On Fri, Jan 12, 2007 at 12:42:15PM +0200, Yorick Hardy wrote:
> > >Yes. Maybe it should be better to add this as a parameter to
> > >bus_dmamap_create(), and compute the proper _dm_bounce_thresh at this
> > >time. But this is a big change in the bus_dma API, and require
> > >changing a lot of files, unless we keep bus_dmamap_create() as is and
> > >intruduce a new function with this extra parameter.
> > >
> > >  
> > Is there an advantage to passing by parameter rather than by flag (as in 
> > my patch) ?
> 
> This is a gross hack, a flag is meant as a boolean, not an arbitrary
> value. And this doesn't handle bus_dmamem
> 
> > Obviously my patch limits the address to a power of 2, will this be a 
> > problem?
> 
> And it can't sepcify a minimum address.

Do we add "bus_addr_t minaddr, bus_addr_t limit" arguments to the affected
functions, or perhaps "bus_addr_t addrbits" (where only lowest and highest
bit set are considered)?

> > I think the patch I proposed may address the above paragraph without the 
> > need to
> > change many files.
> 
> I'd prefer to do it properly, even if we need to change many files.

Agreed.

	-- Jachym